The present invention relates to an image forming apparatus capable of setting the proper end margins of a recording sheet.
Setting of the end margins on a recording sheet (for determining the position of the recording sheet where the image begins) has been carried out by an operator having print position check data printed in the inspection step of an image forming apparatus and visually checking the print position for the amounts of misalignment.
On the other hand, there is an image forming apparatus (see, e.g., Japanese Patent Application Laid-Open Publication No. 2002-283676) designed to automatically set the end margins by using a recording sheet marked at given positions and passing the sheet through the image forming apparatus during setting of the end margins of a recording sheet.
Thus, in conventional image forming apparatuses, end margin setting has been achieved through the operator setting or by use of a special recording sheet.
However, the end margins of a recording sheet vary depending upon factors such as the sheet transfer speed, the recording sheet qualities (e.g., elasticity, thickness), the conditions of the sheet feed unit (sheet feed in the main unit, secondary sheet feed), the sheet feed method and the individual difference in the image forming apparatus. Under such varying conditions, it has been extremely difficult to properly set the end margins of a recording sheet, thus resulting in the need to repeat the setting process a number of times until the end margins of the recording sheet are properly set. This has entailed a large amount of labor and time in the adjustment task in the inspection step, making the task extremely inefficient. On the other hand, the end edges of a recording sheet vary also with secular changes in the apparatus, necessitating the user to set the end margins by eliminating the effects of the print conditions and secular changes and using the margin adjustment and other functions in order to secure the proper end margins.